i bought it through global light-- a supplier on the mms site. i got both the mms, the citric acid and a timer for 25 dollars. i like buying from them. they also have other stuff i may try after i have been on mms for about 6 months or so.
i use citric acid as an activator alternately with lime juice. the lime juice taste better and feels gentler on my system--but thats just me.
when i use it as an enema or a douche or apply it topically (diluted) i use mms with citric acid activator.